In the art of forming and compounding polymeric compositions, impurities can be introduced into the polymeric compositions. These impurities can include secondary and tertiary amines, and can stem from contamination, the use of amine-containing initiators, the presence of amine functionalized polymers, from various compounding additives such as accelerators, or from certain short-stopping reagents used in emulsion polymerization.
While it is known that amines will react with isocyanates, their use in polymeric compositions has not been found to be suitable. The literature has disclosed the use of several methods for trapping secondary amines within rubber compositions. These methods include reacting the secondary amines with isocyanates, or by acetylation with anhydrides. Such methods, however, have been unacceptable inasmuch as the use of anhydrides within rubber compositions results in poor distribution of the inhibitors, and the use of isocyanates tends to react with other rubber additives. Other known methods for removing amines from rubber compositions include the addition of aldehydes, as well as the addition of mono-functional or multi-functional isothiocyanates.
Often, however, the reactants that are added to rubber compositions for scavenging amine impurities have a deleterious impact on the rubber composition and its intended purpose. There is, therefore, a need for amine reactants that do not adversely impact the rubber compositions to which they are added.